Multiplexed Telecommunication-Band Quantum Networking with Atom Arrays in Optical Cavities

Abstract

The disclosure includes a multiplexed telecommunication-band quantum network that utilizes atomic arrays in optical cavities. An example quantum networking system includes at least one quantum repeater node. The quantum repeater node includes an array of neutral atoms disposed in an optical cavity and a fiber-optic switch (FOS). The FOS is optically coupled to the optical cavity. The quantum repeater node also includes at least one beamsplitter. The at least one beamsplitter is optically coupled to the FOS.

We claim: 
     
         1 . A quantum networking system comprising:
 at least one quantum repeater node, wherein the quantum repeater node comprises:
 an array of neutral atoms disposed in an optical cavity; 
 a fiber-optic switch (FOS), wherein the FOS is optically coupled to the optical cavity; and 
   at least one beamsplitter, wherein the at least one beamsplitter is optically coupled to the FOS.   
     
     
         2 . The system of  claim 1 , wherein the quantum repeater node is configured to perform high-rate multiplexed entanglement generation. 
     
     
         3 . The system of  claim 1 , wherein the quantum repeater node is configured to operate within a telecommunication wavelength band between 1260 nm and 1675 nm. 
     
     
         4 . The system of  claim 1 , wherein the array of neutral atoms comprises a plurality of neutral ytterbium ( 171 Yb) atoms. 
     
     
         5 . The system of  claim 1 , wherein the array of neutral atoms comprises a linear arrangement of neutral atoms with an array length of between 100 microns and 300 microns. 
     
     
         6 . The system of  claim 1 , wherein the array of neutral atoms comprises a linear array of between 5 and 500 neutral atoms. 
     
     
         7 . The system of  claim 1 , wherein at least a portion of the neutral atoms of the array of neutral atoms are configured to perform Rydberg entangling operations. 
     
     
         8 . The system of  claim 1 , wherein the optical cavity comprises a pair of near-concentric mirrors. 
     
     
         9 . The system of  claim 8 , wherein the near-concentric mirrors are spherically symmetric. 
     
     
         10 . The system of  claim 8 , wherein the pair of near-concentric mirrors are separated by a mirror spacing of between 0.25 cm and 2.0 cm. 
     
     
         11 . The system of  claim 1 , wherein the array of neutral atoms is formed by using one or more optical tweezers. 
     
     
         12 . The system of  claim 1 , wherein the system further comprises a photon detector (PD) that is optically coupled to the optical cavity via the beamsplitter, wherein the PD is configured to provide information indicative of which atoms at each of the quantum repeater nodes are in a Bell state. 
     
     
         13 . The system of  claim 1 , wherein the system further comprises a further quantum repeater node, wherein the further quantum repeater node comprises:
 a further array of neutral atoms disposed in a further optical cavity; and   a further FOS, wherein the further FOS is optically coupled to the at least one beamsplitter, wherein the further array of neutral atoms is configured to generate a quantum entangled Bell pair with respect to the array of neutral atoms.   
     
     
         14 . The system of  claim 13 , wherein the system provides a distributed, fault-tolerant, quantum computer. 
     
     
         15 . The system of  claim 13 , wherein a Bell pair comprises a two-qubit quantum state. 
     
     
         16 . The system of  claim 13 , wherein the system is configured to provide 25 or more Bell pairs. 
     
     
         17 . The system of  claim 16 , wherein the Bell pairs undergo an entanglement purification process to produce Bell pairs with higher fidelity. 
     
     
         18 . The system of  claim 13 , wherein the system further comprises a further PD, wherein the further PD is optically coupled to the at least one beamsplitter, wherein the further PD is configured to provide information indicative of which atoms in the further array of neutral atoms are in a Bell state. 
     
     
         19 . A quantum networking method comprising:
 providing a first array of neutral atoms in a first quantum repeater node;   providing a second array of neutral atoms in a second quantum repeater node;   performing atom-photon entanglement of at least one neutral atom of the first array of neutral atoms via a four-wave mixing process so as to form a plurality of atom-photon Bell pairs;   distributing entangled Bell pairs between the first quantum repeater node and the second quantum repeater node; and   performing an entanglement purification processes on two or more Bell pairs to produce at least one new Bell pair with higher fidelity.   
     
     
         20 . The method of  claim 19 , wherein providing the array of neutral atoms is performed by way of one or more optical tweezers.